b727pic

iTrader: (1)

I am running a Procharger with the newer style ATI surge valve. There seems to be a great deal of discussion regarding the Mondo bypass valve. I have seen these valve installed where the bypass is vented to atmosphere and I have seen them reroute the bypass air back into the intake plenum to the SC.

what are the pro's and con's of either set up?

is there any benefit to changing to the Mondo valve or a similar vortech unit over the ATI surge valve.

DeltaT

iTrader: (5)

If you are running a MAF system you must vent back into the system or you screw up your air metering.

On a speed density system you can vent outside if you want, but it is generally noisier.

I run the Mondo output right back into the blower inlet, and I can not hear it working ever.

Jim

S_J_H

With it vented to air you'll get a much cooler running head unit and up to a 40' drop in cruise speed discharge temps. The only real drawback is that it is noisy.

You can run it vented to air with a maf. The maf needs to be on the pressure side and the bypass placed well before the maf.I ran mine like that for a couple of years before doing away altogether with any bypass valve and building a blower throttle.

Steve

Ferocity02

iTrader: (60)

Not true. You must NEVER run a bypass or BOV after the MAF sensor, even if you are venting backing into the blower. Also, venting the atmosphere is completely safe even if you have a MAF sensor. Ideally, the BOV or bypass valve should be far away from the MAF sensor to reduce turbulence through the MAF as much as possible when venting. I ran a Procharger with the bypass in the plenum venting to atmosphere and had no issues at all. You are right about screwing up the metering, but thats only if you have the bypass after the MAF sensor.

Back to the original question. You can do either. Recycling the air is good because it means your air filter will be doing less work. Venting to atmosphere means your air filter is cleaning the air for no reason because it's just ending up back outside of the car again. Recycling the air however will result in higher blower and intake temps as mentioned. The air coming out of the valve will ultimately be warmer than the air coming into the blower, unless you have one hell of an intercooling system, such as not the Procharger intercoolers. Venting to atmosphere is quite loud. At about 2000rpm, with the hood open and standing over the motor, my ATI Race bypass valve would make enough noise to make you want to cover your ears. But boy does it sound awesome. Hearing the bypass valve will allow you to make sure that it is opening and closing when it should. This is the opposite for recycling the air as it is almost dead silent. Also, the Mondo or ATI Race bypass valves can vent more air than the standard ATI bypass valve, which can be useful for higher boost applications.

b727pic

iTrader: (1)

Thanks guys....My GTO procharger setup is working fine. I am running a MAF past the intercooler just prior to entering the TB per the ATI instruction manual. But to be honest the bypass valve is louder than I care for....I want as stealthy as possible.

My first plan is to relocate the IAT sensor so that it is actually looking at what it stands for. Next I think I will sacrifice the K&N airfileter by cutting a hole in the end of it ...inserting a threaded pipe and hook my discharge air out of the ATI bypass valve into my new recirculating system. With the relocated IAT I will be able to tell what effect it is having. This seems like an economical test to see what the effect will be. If I like it, I can always add the Mondo or vortech valves and weld in the appropriate fittings.

DeltaT

iTrader: (5)

I was referring to the bypass after the MAF. Guess I should have been more specific.

Jim

DeltaT

iTrader: (5)

With a large A2A FMIC, why would I get a cooler running head unit? I could see this on a non-IC system but...

Thanks,

Jim